[EricH]

Originally Posted by EricVanWyk

I'm also not a battery expert, but I've lived with one and worked with another. I believe the LiFePO4 chemistry to be sufficiently safe for FRC usage. They would be perfect if they didn't cost so much.

Or have so much shipping hassle.

I've had some dealings with LiFePO4 batteries--my Lunabotics team used two of them to run a robot. They acted just like SLAs would have (barring chemistry and mass considerations) but gave us no end of headaches getting them shipped down there and back to South Dakota. Apparently to ship them via ground (you can't ship them via air) you have to have a person with some sort of safety certificate to ship them (thankfully, you don't have to have one to receive!)

R/C lithium batteries tend to be dangerous primarily when they are a) punctured or b) charging or c) very hot. If you're charging them, stick them in a flameproof container and set a timer--they should come out all right unless there's some other flaw. If they get puffy, they're considered bad--there's a procedure to safely make them lose all chance of causing problems, involving salt water and puncturing the battery, IIRC. Otherwise, keep them out of heat.